This comic makes fun of the constant battle between those who maintain a prescriptive view of language and those who have a descriptive view. In the prescriptive view, language has fixed rules and fixed usage, and any usage that does not adhere to established rules is incorrect. In the descriptive view however, language is malleable and any usage can be correct if it is common and understood by most people.

The comic specifically calls out two phrases which are commonly misused in the prescriptive sense, and whose meanings have changed in modern usage in the descriptive sense:

Nauseous

Nauseous in its supposedly 'proper' form means "causing nausea", while nauseated means affected with nausea.

Prescriptively speaking, it is only correct to use the word "nauseous" to describe the food item since that was the cause of Ponytail's nausea. Saying "the food made her nauseous" would be interpreted, by a prescriptivist, as meaning the food somehow caused her (her body, her appearance, etc.) to become so disgusting that she now causes other people to feel nausea. As White Hat states, the proper phrasing is that the "the food was nauseous", and it "made [her] feel nauseated".

Both historically and in modern usage, however, "nauseous" is a valid synonym of "nauseated". It is difficult, if not impossible, to cite an era of history when most people would not understand "she is nauseous" to mean she does not feel well.

Begging the question

Begging the question originally referred to a logical fallacy where an argument assumed its conclusion. The phrase first meant to question (beg) the original question. In modern usage, it has come to mean to "raise a question or point that has not been dealt with". This is often a point of contention for prescriptivists. However, as the caption explains, Cueball has an entirely different meaning for this phrase that he created himself: "fight a losing battle against changing usage". This is actually a meta-meaning, as that is actually the common activity of prescriptivists who complain about incorrect usage; it's a losing battle, because language change is inevitable and unstoppable. And specifically, trying to preserve the original meaning of "begging the question" is a losing battle.

Ponytail might recognize that her exposure to nauseous food has both nauseated her and caused her to become nauseous to Cueball. The question is not merely begged it is missed.

The title text also plays on another word commonly argued over by prescriptivists. "Enormity" in its classical usage means either extreme wickedness or a monstrous offense or evil, though it is more commonly used in modern writing as a synonym for enormousness (i.e. largeness in size). The title text exploits the lexical ambiguity that this creates.

Discussion

Of course it's also possible that the food made them so Nauseated that they also became Nauseous (i.e. they could have started vomiting or smell horrible due to eating the food, causing people around to feel unwell as well). NormanR (talk) 21:13, 29 August 2018 (UTC)

I concur, I imagine Randall had an alternate ending in mind where cue-ball says "No, she's right, I'm nauseated just being around her" 108.162.221.35 19:07, 30 August 2018 (UTC) Sam

I believe the reason the two words have become confused is due to the word "noxious". which means "very unpleasant". So, someone who is "nauseated" could feel "noxious", and when wires end up crossed in the brain, they associate it with "nauseous" rather than "noxious". 108.162.241.166 (talk) (please sign your comments with ~~~~)

But "noxious" means harmful, poisonous, unpleasant, which is different than "having an unpleasant feeling." Here again, the word "unpleasant" has undergone a shift in usage from "not pleasing" to something more like "displeased" as in the statement "I feel unpleasant," used to mean "I have an unpleasant feeling." 162.158.75.46 04:57, 30 August 2018 (UTC)

Except that the secondary meaning of nauseous has been around for as long as the primary meaning. It is only recent pedantry that has tried to suppress the more ancient use. 108.162.237.58 (talk) (please sign your comments with ~~~~)

I shall follow this argument with complete disinterest Arachrah (talk)

I looked up "Nauseous" in Dictionary.com and I found the following usage note:

"The two literal senses of nauseous, “causing nausea” ( a nauseous smell ) and “affected with nausea” ( to feel nauseous ), appear in English at almost the same time in the early 17th century, and both senses are in standard use at the present time. Nauseous is more common than nauseated in the sense “affected with nausea,” despite recent objections by those who imagine the sense to be new. In the sense “causing nausea,” either literally or figuratively, nauseating has become more common than nauseous : a nauseating smell."

So, originally, it seems Nauseous was used to refer to both the object that causes the nausea, as well as the feeling. So this is not really a case of change of use, but more your typical snobbish people trying to appear smarter by correcting other people's language usage. The spirit of the comic remains, though. Source141.101.99.23 (talk) (please sign your comments with ~~~~)

I'm 41 years old, and I have never heard the usage of nauseous meaning causing nausea until today. I speak American English. -- WhiteDragon (talk) 17:01, 30 August 2018 (UTC)

xkcd is a webcomic of romance, sarcasm, math, andlanguage. Try Google with this search phrase: "nauseated vs. nauseous". One example:

The English purists argue that, when “nauseous” entered the language from Latin, it meant only “causing nausea,” as the smell of an overfull vomit bag might, ... . “Nauseated,” on the other hand, means “afflicted with nausea,” like how that poor chap who filled the vomit bag feels, and should never, ever be substituted with “nauseous.”

Apparently you don't watch Big Bang Theory, :) That's the most visible example I've seen of it being pointed out that "nauseous" means "causes nausea", that the standard usage is using it when we're supposed to use "nauseated". I've seen this pointed out enough that I try to remember to say "nauseated" on the rare occasions it comes up. :) NiceGuy1 (talk) 05:40, 2 September 2018 (UTC)

TIL: "Enormity" and "Begs the question" didn't originally mean what I've always known them to mean, LOL! At least with the latter the original meaning makes more sense, with that wording. NiceGuy1 (talk) 05:40, 2 September 2018 (UTC)

"Beg the question" has actually had THREE distinct meanings: originally it was to BEGGAR the question, meaning (as stated above) to void the question of any meaning by assuming the answer in advance. This morphed into "beg the question", which gradually shifted meaning into a statement which was so problematic it couldn't go unchallenged (it begs "the question" meaning it begs to BE QUESTIONED). Now we live in the era of "...which begs the question: (whatever question the referenced thing suggests)" Who knows what cool new meaning it'll have in a few hundred years? 162.158.79.65 02:20, 1 October 2018 (UTC)

A lot of the usage of the English language varies depending on region. Interestingly, I've never encountered "nauseous" being used to describe an item, only the sensation. I suspect there is some historical confusion with the word "noxious" due to the highly varied (non-standardized) spelling of early modern English. In my experience and usage, one would say that the food is either "noxious" (causing harm through unpleasant sensations) or "nauseating" (simply causing nausea), the latter of which I am surprised no one else has yet mentioned (hence my desire to comment). However, I doubt any of these constructs can really be stated to be the only correct grammatical form, as usage varies too wildly. In fact, the version suggested by White Hat seems to be going the way of the dodo anyway, as alluded to by Cueball. 162.158.118.46 10:36, 13 January 2019 (UTC)